Series I contains material relating to Gabriele's career as a freelance singer from the 1940s through the 1970s. The series covers a range of opera, recital, and concert performances both in the United States and in Europe (with Gabriele's Italian performances particularly well represented). The bulk of this series consists of programs, publicity material, and press clippings relating to these performances, but also includes correspondence, administrative documents, photographs, sheet music, and some recordings. Scores in this series (many of which are annotated) document her collaborations with a number of contemporary American and Italian composers, including Douglas Moore, Jack Beeson, David Amram, and Vincent Persichetti. Notable performances featured in this series include Gabriele's early recital work in West Virginia in the 1940s, her 1958 recital at the New York Town Hall, her performances at Central City Opera and other regional opera houses, and her 1959 performance of La bohème at the Teatro di San Carlo. Notably, this series features a number of rare, unreleased recordings of Gabriele's opera and concert performances (including world premieres) and also recordings of Gabriele's singing lessons with Laszlo Halasz. Note that although Gabriele sang in recitals and operas with the Masterworks Laboratory Theater, these materials are held under Series II, alongside documents relating to her directorial work. And although Gabriele performed frequently at Chez Vito, this facet of her vocal career is housed under Series III.